How can many faces be mapped to a texture?
My advice is to switch your leave settings from Hexoganol to Rectangular. This will make single planes without cuts (extra edges) with 1 origin and it will unwrap as a single plane (like resetting the uv map). It is then easier to make adjustments for the direction of the leaves and will effect all the leaves in the same way (from the root). I don't know of any other workflow's for this situation.